conditional formatting makes Calc Crash every day. Sorry i’m tired to give more informations. Just test it. It´s easy to prove.The conditional formatting is in a mess completely.
Please try resetting the user profile, sometimes solves strange issues.
https://wiki.documentfoundation.org/UserProfile
Usually it’s enough renaming/deleting the file “user/registrymodifications.xcu”, it affects all the options in Menu/Tools/Options, and the files “user/basic/dialog.xlc” and “scrip.xlc” are overwritten, additionally custom colors in “user/config/standard.soc” are lost.
not the right answer, it’s sure to be a bug, all version tested since V4.0
Have you reported the bug? http://www.libreoffice.org/get-help/feedback/. The crystal ball were lost.